元素分析仪同时测定土壤中的全氮和总碳

Concurrent determination by elemental analyzer of total nitrogen and total carbon in soil samples

采用氧化燃烧-气相色谱法,以水系沉积物和土壤国家一级有证标准物质建立曲线,使用元素分析仪测定土壤中的全氮和总碳,各元素检出限均满足化探要求。通过12次重复测试国家一级有证标准物质GBW07448、GBW07447、GBW07423、GBW07309、GBW07456和GBW07457,检验方法准确度和精密度均符合中华人民共和国地质矿产行业标准。选取北京地区土壤样品重复测试,数据表明,全氮的相对偏差为0~4.76%,总碳的相对偏差为0.95%~4.53%。华北有色地质勘查局燕郊中心实验室用凯氏定氮法和高频燃烧红外吸收光谱法分别测试全氮和总碳,与本方法作对比,数据表明,全氮的相对偏差为0~9.09%,总碳的相对偏差在0~5.67%内。

Total nitrogen and total carbon in soil are determined using the method of oxidation-combustion-gas chromatography.In doing so, a curve is established using national certified reference materials of stream sediments and soil, and an element analyzer model EA3000 made by Eurovector of Italy is applied, and the detection limits of each element meet the requirement of geochemical exploration. The accuracy and precision of GBW07448, GBW07447, GBW07423, GBW07309, GBW07456 and GBW07457, which are certified reference materials of the first class in China, is tested 12 times, all in accordance with the standards of geological and mineral industry of the People’s Republic of China. In order to verify the accuracy of the method in the actual sample measurement, 35 soil samples from Beijing are selected for repeated test in the laboratory.The data show that the relative deviation of total nitrogen is 0-4.76%, and the relative deviation of total carbon is 0.95%-4.53%. Another 35 samples are tested in two laboratories. The results show that the relative deviations of total nitrogen and total carbon are 0-9.09% and 0-5.67% respectively.The method has the advantages of fast speed, low pollution and few errors in soil determination.